In interoperable road communication systems radio beacons must be able to interact with a plurality of onboard units of different manufacturers, which respectively have different message transmission and receive characteristics or capabilities, such as transmitting power, receive sensitivity, bandwidth, latency, scope of data etc. This situation is exacerbated further by the circumstance that the vehicles carrying the onboard units travel past the radio beacon at different speeds and in different directions, which causes a further disparity in the times and channel qualities of transmission available for message transmission.